I have a colleague who is as much an advocate of the IntelliJ IDE for Java, as I am for Eclipse. So far, in the ‘My Java Tool is better than yours’ game, I can claim the low cost (free), the number of plugins (huge) and number of developers using it (no figures, but I suspect Eclipse is now the development platform of choice). His trump card for Intellij is that ‘you download it and it just works’ – no messing around with installing plugins for stuff like JSP and Enterprise Java editing.
While plugins are always going to be slightly messy (you don’t get the gain of extensibility without some pain in the form of configuration), the Eclipse Callisto release , due in July, is another step in the right direction. It is a simultaneous release of 10 major Eclipse projects, including BIRT (reporting tools), Data Tools, Eclipse Web Tools, the Visual Editor , Test and Performance Tools and the Graphical Modelling Framework.
It may not be a ‘download from one place and it just works’, but by removing any integration issues, it will make your life easier.
Paul Browne 
In the meantime, if you’re looking for an ‘all in one’ Eclipse based IDE solution, you could do worse than check out the JBoss IDE